Write size was not correctly alligned to SECT_SIZE. This lead to situation

where trim corrupted the database. Fixed the issue and added temporal 
guards against unalligned write/trim.

storage/innobase/fil/fil0pagecompress.cc

@@ -188,9 +188,13 @@ fil_compress_page(
 #endif /* UNIV_DEBUG */
 
 	write_size+=header_len;
+
+#define SECT_SIZE 512
+
 	/* Actual write needs to be alligned on block size */
-	if (write_size % OS_FILE_LOG_BLOCK_SIZE) {
-		write_size = (write_size + (OS_FILE_LOG_BLOCK_SIZE - (write_size % OS_FILE_LOG_BLOCK_SIZE)));
+	if (write_size % SECT_SIZE) {
+		write_size = (write_size + SECT_SIZE-1) & ~(SECT_SIZE-1);
+		ut_a((write_size % SECT_SIZE) == 0);
 	}
 
 #ifdef UNIV_DEBUG
@@ -199,7 +203,6 @@ fil_compress_page(
 		space_id, fil_space_name(space), len, write_size);
 #endif
 
-#define SECT_SIZE 512
 
 	srv_stats.page_compression_saved.add((len - write_size));
 	if ((len - write_size) > 0) {

storage/innobase/os/os0file.cc

@@ -6151,9 +6151,10 @@ os_file_trim(
 
 #define SECT_SIZE 512
 	size_t trim_len = UNIV_PAGE_SIZE - len;
-	// len here should be alligned to sector size
-	ut_a(trim_len == ((trim_len + SECT_SIZE-1) & ~(SECT_SIZE-1)));
 	os_offset_t off = slot->offset + len;
+	// len here should be alligned to sector size
+	ut_a((trim_len % SECT_SIZE) == 0);
+	ut_a((len % SECT_SIZE) == 0);
 
 	// Nothing to do if trim length is zero or if actual write
 	// size is initialized and it is smaller than current write size.

storage/xtradb/fil/fil0pagecompress.cc

@@ -184,9 +184,13 @@ fil_compress_page(
 #endif /* UNIV_DEBUG */
 
 	write_size+=header_len;
+
+#define SECT_SIZE 512
+
 	/* Actual write needs to be alligned on block size */
-	if (write_size % OS_FILE_LOG_BLOCK_SIZE) {
-		write_size = (write_size + (OS_FILE_LOG_BLOCK_SIZE - (write_size % OS_FILE_LOG_BLOCK_SIZE)));
+	if (write_size % SECT_SIZE) {
+		write_size = (write_size + SECT_SIZE-1) & ~(SECT_SIZE-1);
+		ut_a((write_size % SECT_SIZE) == 0);
 	}
 
 #ifdef UNIV_DEBUG
@@ -195,7 +199,6 @@ fil_compress_page(
 		space_id, fil_space_name(space), len, write_size);
 #endif /* UNIV_DEBUG */
 
-#define SECT_SIZE 512
 
 	srv_stats.page_compression_saved.add((len - write_size));
 	if ((len - write_size) > 0) {

storage/xtradb/os/os0file.cc

@@ -6206,9 +6206,10 @@ os_file_trim(
 
 #define SECT_SIZE 512
 	size_t trim_len = UNIV_PAGE_SIZE - len;
-	// len here should be alligned to sector size
-	ut_a(trim_len == ((trim_len + SECT_SIZE-1) & ~(SECT_SIZE-1)));
 	os_offset_t off = slot->offset + len;
+	// len here should be alligned to sector size
+	ut_a((trim_len % SECT_SIZE) == 0);
+	ut_a((len % SECT_SIZE) == 0);
 
 	// Nothing to do if trim length is zero or if actual write
 	// size is initialized and it is smaller than current write size.